From 036a9bbd0be2b71fc9d60954fd0b1b64c9a181af Mon Sep 17 00:00:00 2001 From: Jason Zaugg Date: Fri, 26 Sep 2014 09:24:50 +1000 Subject: SI-8079 Only expand local aliases during variance checks We've been flip-flopping on this one through the years, right now we issue an two errors for the enclosed test. After this commit, variance validation only expands aliases that are `{private,protected}[this]`. The rest need not be expanded, as we have already variance validated the RHS of the alias. It also removes a seemingly incorrect check in `isLocalOnly`. This also means that we can use `@uncheckedVariance` to create variant type aliases for Java interfaces. However, if such a type alias is declared private local, it *will* be expanded. That shouldn't be a problem, other than for the fact that we run through an as-seen-from that strips the `@uV` annotations in the type expansion. This has been recorded in a pending test. --- test/files/neg/t8079a.check | 4 ++++ test/files/neg/t8079a.scala | 4 ++++ test/files/neg/variances.check | 2 +- 3 files changed, 9 insertions(+), 1 deletion(-) create mode 100644 test/files/neg/t8079a.check create mode 100644 test/files/neg/t8079a.scala (limited to 'test/files/neg') diff --git a/test/files/neg/t8079a.check b/test/files/neg/t8079a.check new file mode 100644 index 0000000000..6bbe78afa6 --- /dev/null +++ b/test/files/neg/t8079a.check @@ -0,0 +1,4 @@ +t8079a.scala:3: error: contravariant type I occurs in covariant position in type C.this.X of value b + def f2(b: X): Unit + ^ +one error found diff --git a/test/files/neg/t8079a.scala b/test/files/neg/t8079a.scala new file mode 100644 index 0000000000..4997ea282e --- /dev/null +++ b/test/files/neg/t8079a.scala @@ -0,0 +1,4 @@ +trait C[-I] { + private[this] type X = C[I] + def f2(b: X): Unit +} diff --git a/test/files/neg/variances.check b/test/files/neg/variances.check index cb1a60a632..3c1545a375 100644 --- a/test/files/neg/variances.check +++ b/test/files/neg/variances.check @@ -19,7 +19,7 @@ variances.scala:74: error: covariant type A occurs in contravariant position in variances.scala:89: error: covariant type T occurs in invariant position in type T of type A type A = T ^ -variances.scala:90: error: covariant type T occurs in contravariant position in type => test.TestAlias.B[C.this.A] of method foo +variances.scala:90: error: covariant type A occurs in contravariant position in type => test.TestAlias.B[C.this.A] of method foo def foo: B[A] ^ 8 errors found -- cgit v1.2.3